Giwoon Kim

Pathophysiology of brain injuries in acute carbon monoxide poisoning: A novel hypothesis

Acute carbon monoxide (CO) poisoning causes the neurologic symptoms and brain lesions during both acute and delayed phase. We propose that catecholamine crises in globus pallidus and deep white matter are the key pathophysiological factors causing acute and delayed brain injuries respectively. Increased sympathetic activities due to acute CO poisoning is followed by increases of catecholamine levels in synapses or nerve terminals in organs including the brain, especially, limbic system. A dopamine excess in the synaptic cleft of the mesolimbic system, including globus pallidus, may cause the destruction of synapses and nuclei in the globus pallidus. Consequently, the striatal lesion is affected in the acute phase of CO intoxication. Moreover, an increase of catecholamine levels in synapses of deep white matter can persist after the acute stage of CO intoxication. A dopamine excess could lead to oxidative metabolism of dopamine, serotonergic axonal injury, or secondary myelin damage.

Outcome and current status of therapeutic hypothermia after out-of-hospital cardiac arrest in Korea using data from the Korea Hypothermia Network registry

Objective Therapeutic hypothermia (TH) has become the standard strategy for reducing brain damage in the postresuscitation period. The aim of this study was to investigate current TH performance and outcomes in out-of-hospital cardiac arrest (OHCA) survivors using data from the Korean Hypothermia Network (KORHN) registry. Methods We used the KORHN registry, a web-based multicenter registry that includes 24 participating hospitals throughout the Republic of Korea. Adult comatose OHCA survivors treated with TH between 2007 and 2012 were included. The primary outcomes were neurological outcome at hospital discharge and in-hospital mortality. The secondary outcomes were TH performance and adverse events during TH. Results A total of 930 patients were included, of whom 556 (59.8%) survived to discharge and 249 (26.8%) were discharged with good neurologic outcomes. The median time from return of spontaneous circulation (ROSC) to the start of TH was 101 minutes (interquartile range [IQR], 46 to 200 minutes). The induction, maintenance, and rewarming durations were 150 minutes (IQR, 80 to 267 minutes), 1,440 minutes (IQR, 1,290 to 1,440 minutes), and 708 minutes (IQR, 420 to 900 minutes), respectively. The time from the ROSC to coronary angiography was 1,045 hours (IQR, 121 to 12,051 hours). Hyperglycemia (46.3%) was the most frequent adverse event. Conclusion More than one-quarter of the OHCA survivors (26.8%) were discharged with good neurologic outcomes. TH performance was appropriately managed in terms of the factors related to its timing, including cooling start time and rewarming duration.

The pattern of Tpeak-Tend and QT interval, and J wave during therapeutic hypothermia.

BACKGROUND AND PURPOSE The electrocardiogram manifestations of hypothermia include J waves and prolongation of QT intervals. This study described changes in repolarization patterns during therapeutic hypothermia (TH). METHODS We measured the QTc and the interval from the peak to the end of the T wave (TpTe) from the V4 and V6 leads in 20 patients with TH. The TpTe was also expressed as a ratio to the duration of QT ([TpTe/QT]×100%), and to the corrected value for heart rate (TpTe/√RR). RESULTS The QTc became prolonged in all patients during TH. While the TpTe/√RR did not change, the ([TpTe/QTe]×100%] decreased significantly during TH. The J wave developed during TH in seven patients. With one patient, ventricular fibrillation occurred preceded by an abnormal J wave and prolonged TpTe during TH. CONCLUSIONS QTc prolongation without TpTe increase or abnormal J wave may not be arrhythmogenic during TH.

Outcomes of hanging-induced cardiac arrest patients who underwent therapeutic hypothermia: a multicenter retrospective cohort study.

OBJECTIVES The aim of this study was to analyze the outcomes of patients with hanging-induced cardiac arrest who underwent therapeutic hypothermia (TH). METHOD In this multicenter, retrospective registry-based study, discharged patients after out-of-hospital cardiac arrest and treatment with TH were enrolled between June 2007 and March 2013. Several prehospital and hospital variables were examined for an outcome analysis with multivariable logistic regression. RESULTS A total of 964 patients who had cardiac arrest were enrolled in this study. All patients underwent TH during post-cardiac arrest care after return of spontaneous circulation (ROSC). Of all patients, 105 were assigned to the hanging group and 859 to the non-hanging group. Six patients (6%) with good neurologic outcomes (Cerebral Performance Category 1 or 2) in the hanging group at the time of discharge were found. A shorter time interval between witnessed arrest and ROSC and a Glasgow Coma Scale over 4 after ROSC are statistically significant variables of good neurologic outcomes after hanging-induced cardiac arrest treated with TH. CONCLUSION A small number of patients who underwent TH after a hanging-induced cardiac arrest provided good neurologic outcomes, and some variables influenced these outcomes.

Effectiveness of a compressive device in controlling hemorrhage following radial artery catheterization

Objective The purpose of this study was to evaluate the effectiveness of a compressive device in controlling hemorrhage following radial artery catheterization. Methods A prospective randomized trial was conducted on subjects receiving the standard taping method (group S) compared to a compressive device method (group C) after removal of the cannula in radial artery catheterization. Primary outcomes were the success rate of hemostasis and complication rate after cannula removal. Secondary outcomes were the cost of compression and the level of convenience. Results A total of 250 subjects were enrolled in this study. Hemostasis after removal was successful in 122 of 125 (97.6%) subjects in group S and 116 of 125 (92.8%) subjects in group C (P=0.18). Complication rates in group S and group C were 55.2% (69/125) and 48% (60/125), respectively (P=0.35). The cost of compression for group C (approximately 6,740 Korean won) was approximately two times cheaper than for group S (approximately 14,140 Korean won). The level of convenience was significantly higher in group C than in group S (7.4±2.1 vs. 3.7±1.9, p < 0.001). Conclusion These findings suggest that hemostasis using a compressive device may be a suitable alternative method to the standard taping method in controlling hemorrhage following radial artery cannulation.

Clinical applications and contemporary trends of hyperbaric oxygen therapy in Korea

고압산소치료란 고농도의 산소를 높은 압력으로 환자에 게 투여하는 치료법으로, 100% 산소와 최소 1.4기압 이상 의 압력을 사용한다[1]. 혈액을 통해 운반되는 대부분의 산 소는 산소-헤모글로빈 결합 형태로 운반된다. 산소가 산 소-헤모글로빈 결합 형태로 운반되면 산소-헤모글로빈 해 리의 생리적 특징, 즉 헤모글로빈 완충작용 때문에 공급되 는 산소농도가 60-120 mmHg 사이로 변한다 해도조직에 공급되는 산소농도는 일정하게 유지될 수 있다. 정상기압에 서 혈장 용존 산소는 단지 100 mL의 혈액 중 0.3 mL(이를 volumes perscent [vol%]라고 한다)이며, 반면에 헤모글로 빈에 의한 것은 20 mL (20vol%)이다. 기압을 3기압으로 올 리면 PaO2는 2,200 mmHg에 달하며 이는 혈장 용존 산소 량은 5.4vol%로써 정상 0.3vol%의 18배 정도까지 증가하게 된다. 그러므로 이렇게 높아진 산소분압은 헤모글로빈이 완 전히 없어도 기초대사기능을 지속적으로 유지시킬 수 있는 Hyperbaric oxygen therapy (HBOT) is approved in the United States for 14 accepted indications, which are approved by the HBOT committee of the Undersea and Hyperbaric Medical Society and by the Food and Drug Administration. These indications are also used worldwide. HBOT is a mode of medical treatment in which the patient is situated in an enclosed pressure chamber and breathes 100% oxygen at a pressure greater than 1 atmosphere absolute (ATA), with the usual therapeutic pressure set at greater than 1.4 ATA. In South Korea, an expanded knowledge base and formalized education in HBOT do not exist, and numerous HBOT devices are old and nearing the cessation of operation, although HBOT has undergone refinement, with an increased understanding of mechanisms of action and clinical applications. Furthermore, there is no specific board certification of HBO competence for emergency, critical care, and surgical physicians and technicians in South Korea. We summarize the existing literature on the uses of HBO with the aim of enhancing the understanding of this therapeutic technique.

Injuries associated with the 580 km university student grand voluntary road march: focus on foot injuries.

College student volunteers (n = 142) completed a 580 km road march for 21 consecutive days. Each volunteer carried a backpack that weighed 14.1 ± 1.4 kg on the average. We investigated the incidence and location of blisters associated with the road march using a foot map along with other injuries. Overall, 95.1% of the subjects (135 of 142) sustained one or more injuries. All injured subjects had foot blisters, and 18% had other foot injuries. The most common locations of blister development were the right 5th toe (61%) and the left 5th toe (57%). The little toes seem to have been subjected to the greatest friction and shearing forces. March-related injuries, excluding foot injuries, were ankle pain (12.7%), knee pain (12.7%) and Achilles tendon pain (7.7%). Six subjects (4.2%) needed extra medical treatment for more than 2 weeks prior to returning to their daily lives after completion of the march due to associated injuries. The present study observed a very high incidence rate of injuries (95.1%) associated with the 580 km university students grand road march. These injuries posed an obstacle against completion of the road march and against returning to daily life. Active preventive interventions such as physical therapy and customized reinforced shoes and education program are recommended for reducing incidence rate and severity of injuries.

Comparison of internal jugular vein dilation between Valsalva maneuver and proximal internal jugular vein compression

Objective The Valsalva maneuver is recognized as an effective method to dilate the internal jugular vein (IJV). However, this maneuver cannot be performed in many cases, such as children and unconscious patients. The aim of this study was to evaluate the effectiveness of proximal IJV compression, which can easily be performed, regardless of patient cooperation. Methods Healthy adult volunteers were recruited from tertiary hospital employees. Basic anatomic and physiologic data were collected. The subjects lay down as if they were undergoing IJV catheter insertion, in the supine position with their necks turned 30 degrees to the left. The main outcome was the cross-sectional area (CSA) of the distal IJV as measured by ultrasound in four stages. The first stage was sham without any maneuver. The second was Valsalva maneuver, the third was digital IJV compression, and the fourth was digital compression accompanied by simultaneous Valsalva maneuver. Results A total of 41 volunteers were enrolled. Twenty-six (63.41%) were male with an average age of 28.15±2.85 years. Mean height was 170.74±8.66 cm and mean neck circumference was 35.28±3.87 cm. The mean CSA-IJV was 1.06±0.36 cm2 without any maneuver. It increased to 1.34±0.45 cm2 with Valsalva maneuver (P<0.001), to 1.26±0.41 cm2 with digital compression (P<0.001), and to 1.41±0.47 cm2 with the two maneuvers combined (P=0.01). Conclusion Digital proximal IJV compression effectively dilates the distal IJV. When performed simultaneously with the Valsalva maneuver, the effect was enhanced.